| Texto completo | |
| Autor(es): |
Dias, M. E. S.
;
Fuess, L. T.
;
Oliveira, G. H. D.
;
Takeda, P. Y.
;
Carneiro, R. B.
;
Tommaso, G.
Número total de Autores: 6
|
| Tipo de documento: | Artigo Científico |
| Fonte: | BIOMASS & BIOENERGY; v. 206, p. 16-pg., 2026-03-01. |
| Resumo | |
This study investigates the impact of alkaline pretreatment (APT) with sodium hydroxide (NaOH) and buffer supplementation with sodium bicarbonate (NaHCO3) on methane yield (MY) during anaerobic digestion (AD) of industrial spent coffee grounds (SCG), also providing the first microbial taxonomic analysis under these conditions. NaOH pretreatment was applied at concentrations of 1-8 % (m/m, NaOH-to-SCG TS), and its effectiveness was compared to buffering with 2.6 g L-1 NaHCO3 (similar to 0.7 g Na (+) L-1). A mild 1 % NaOH dose increased MY by 42.5 % (from 179.4 to 255.6 mL CH4 g(-1) TS), while bicarbonate addition alone improved MY by 63.8 % (to 293.7 mL CH4 g(-1) TS). However, combining NaOH pretreatment with NaHCO3 proved detrimental at >= 2 % NaOH, reducing methane output. Interestingly, 1 % NaOH with NaHCO3 led to the highest MY (301.1 +/- 6.5 mL CH4 g(-1) TS), but with negligible improvement over NaHCO3 alone, suggesting non-additive effects. MY kinetics (k approximate to 0.50 mL CH4 g(-1) TS d(-1)) remained largely unaffected. Agitation had no statistical impact on MY, confirming mass transfer was not a limiting factor. Microbial analysis revealed bicarbonate addition enriched Acetivibrio, Ruminococcus, and related cellulolytic genera, while its absence favored Syntrophorhabdus, Hydrogenispora, and Syntrophobacter, reflecting a shift from polysaccharide degradation toward aromatic and propionate-oxidizing pathways. These findings emphasize that mild alkali pretreatment or bicarbonate buffering can independently enhance SCG conversion, but their combined use requires careful management. (AU) | |
| Processo FAPESP: | 20/07737-2 - Pré-tratamentos hidrotérmico e químico de resíduos da produção de café solúvel acoplados à metanogênese |
| Beneficiário: | Maria Eduarda Simoes Dias |
| Modalidade de apoio: | Bolsas no Brasil - Doutorado |
| Processo FAPESP: | 22/10615-1 - Consolidação do conceito de biorrefinaria aplicado ao tratamento biológico de águas residuárias e de resíduos sólidos |
| Beneficiário: | Marcelo Zaiat |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 21/15022-6 - Associação de pré-tratamentos e digestão anaeróbia para a valorização energética dos principais resíduos da cadeia produtiva do café |
| Beneficiário: | Giovana Tommaso |
| Modalidade de apoio: | Auxílio à Pesquisa - Regular |